This research evaluates the utilization and costs of computed tomography (CT) scanning for a large heterogeneous population. Factors associated with utilization differential across hospitals and small geographic regions are examined. Independent variables regional analysis include CT scanner density, percent Medicare coverage, percent Medi-Caid coverage, hospital beds/1000 population, regional percent medical specialists and other variables. Independent variables for hospital utilization include percent specialized medical staff, hospital case mix, hospital ownership, teaching programs, volume of scans at non-hospital facilities, and year scanner installed. Cost functions for CT scanning are estimated and analyzed. The relationship of CT costs to charges, other ancillary service costs, hospital-based-physician reimbursement, profit motive, and other hospital and system characteristics are analyzed. The data sources for these studies are mandated annual hospital surveys, discharge abstract summaries, financial disclosure reports required by the State of California and charge surveys. Data on non-hospital and mobile scanner costs and utilization are collected by a survey of these units. Case studies will be conducted in four to six hospitals with CT scanners and newly installed nuclear magnetic resonance units (NMR) in order to determine the extent to which NMR may replace CT as an imaging modality of choice. Cost and utilization forecasts for CT and NMR will be produced. The findings of this research project are significant because of the prominence of CT scanning as a prototype high cost medical technology. While there is a considerable body of knowledge on the diffusion of this medical technology the understanding of its utilization is deficient. These sutdies will add to the body of knowledge on utilization of medical technology as it reaches a steady state. Knowledge of this complete cycle and factors associated with utilization and cost are essential to policymakers and regulators seeking to implement cost containment and utilization control strategies. Information on NMR utilization and its relationship to CT will provide new insights into the newest of imaging technology.